Leakage current and carbon track analysis of LLDPE-natural rubber blends filled with nano silica

Abstract

In outdoor conditions, polymer nanocomposite insulators commonly confront aging due to surface tracking which eventually contribute to breakdown. The evaporation of the wet-contaminated layer on the insulator surface due to extensive flows of leakage current (LC) will cause dry band arcing (DBA) burning the insulator surface and forming the carbon track. The evaluation of the material deterioration degree based on carbon track development is determined by the flows of the LC on the insulator surface. In this paper, the modelling of inclined plane tracking (IPT) test in the field simulation was conducted with references to IEC 60587 standard. The electric field and LC distribution on the linear low density polyethylene (LLDPE) and natural rubber (NR) blends with different percentage of nano-scale filler of silica were studied using finite element method (FEM) analysis. The IPT test was carried out in order to validate the field simulation result and determine the correlation factor (f). The observation of the result from the field simulation and experimental result showed a resemblance in terms of LC patterns. Degradation level from carbon track development of the compositions increases when higher LC flows. The LLDPE-NR/ SiO2 at 1wt% was found to be lowest LC in both experimental and simulation results, and thus is the best composition.